1. Field of the Invention
Embodiments of the invention generally relate to apparatuses and methods for vapor deposition, and more particularly, to chemical vapor deposition systems, reactors, and processes thereof.
2. Description of the Related Art
Photovoltaic or solar devices, semiconductor devices, or other electronic devices are usually manufactured by utilizing a variety of fabrication processes to manipulate the surface of a substrate. These fabrication processes may include deposition, annealing, etching, doping, oxidation, nitridation, and many other processes. Epitaxial lift off (ELO) is a less common technique for fabricating thin film devices and materials in which layers of materials are deposited to and then removed from a growth substrate. An epitaxial layer, film, or material is grown or deposited on a sacrificial layer which is disposed on the growth substrate, such as a gallium arsenide wafer, by a chemical vapor deposition (CVD) process or a metallic-organic CVD (MOCVD) process. Subsequently, the sacrificial layer is selectively etched away in a wet acid bath, while the epitaxial material is separated from the growth substrate during the ELO etch process. The isolated epitaxial material may be a thin layer or film which is usually referred to as the ELO film or the epitaxial film. Each epitaxial film generally contains numerous layers of varying compositions relative to the specific device, such as photovoltaic or solar devices, semiconductor devices, or other electronic devices.
The CVD process includes growing or depositing the epitaxial film by the reaction of vapor phase chemical precursors. During a MOCVD process, at least one of the chemical precursors is a metallic-organic compound—that is—a compound having a metal atom and at least one ligand containing an organic fragment.
There are numerous types of CVD reactors for very different applications. For example, CVD reactors include single or bulk wafer reactors, atmospheric and low pressure reactors, ambient temperature and high temperature reactors, as well as plasma enhanced reactors. These distinct designs address a variety of challenges that are encountered during a CVD process, such as depletion effects, contamination issues, reactor maintenance, throughput, and production costs.
Therefore, there is a need for CVD systems, reactors, and processes to grow epitaxial films and materials on substrates more effectively with less contamination, higher throughput, and less expensive than by currently known CVD equipment and processes.